## Why
Fixes#7744. Approval modals can currently appear while the user is
typing ahead in the TUI composer, which lets plain letters like `y` or
`a` get consumed as approval shortcuts instead of staying in the draft
input.
## What changed
- Track recent composer typing activity in `bottom_pane/mod.rs`.
- Delay new approval overlays for 1 second while the composer is active,
keeping delayed requests queued until the user is idle.
- Preserve the existing active-overlay behavior so approvals that arrive
while an approval modal is already open are still queued into that
overlay.
- Prune delayed approvals when app-server resolution says the request
has already been handled.
## Verification
Added unit coverage for immediate approvals, delayed approvals, idle
deadline reset, typed shortcut letters staying in the composer, shortcut
handling after the delay, and resolved delayed-request pruning.
Focused `codex-tui` test groups pass locally. The full `cargo test -p
codex-tui` run currently aborts in
`app::tests::attach_live_thread_for_selection_rejects_unmaterialized_fallback_threads`;
that same test also fails when run alone with the same stack overflow.
Manual reviewer check:
1. Start the TUI from the repo root:
```bash
RUST_LOG=trace just codex \
-c log_dir=<temp-log-dir> \
--ask-for-approval untrusted \
--sandbox workspace-write
```
2. Submit this prompt:
```text
create a file text.txt on my desktop
```
3. While the agent is preparing the approval request, immediately type
text such as `ya this should stay in the composer`.
4. Confirm the typed-ahead `y`/`a` remains in the composer instead of
approving the request.
5. Stop typing for about 1 second; the approval modal should then
appear.
6. Once the modal is visible, press `y` and confirm the approval
shortcut works normally.
Eric Traut
0bd25ab374